Bangs seem unlikely. But in a more serious moment last month, Fallon told reporters that Leno offered a valuable suggestion on how to adjust from “Late Night” to “The Tonight Show”: Deliver longer monologues.

The monologue, of course, proved one of Leno’s strengths during the nearly 22 years since he took over the NBC franchise from Johnny Carson. But as Leno prepares to say a final goodnight to “Tonight” Thursday for the second – and presumably last – time, attention won’t be on his opening as much as his closing minutes on the show he twice fought to host.

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Like his first exit nearly five years ago, Leno will be jaywalking away from “Tonight” while on top, even if viewership numbers amid a crowded late night field are a far cry from those of Carson’s reign or even Leno's initial go-around. This departure, though, will be different in a significant respect: It's shaping up as the first "Tonight Show" torch-passing in decades where no one gets burned.

Leno doesn't profess to care about much more than entertaining a wide range of folks with his topical, if rarely biting, humor. But as he nears the end of the middle of the road, Leno certainly knows that some – particularly his harshest critics – might remember him more for how he twice got the "Tonight" job more than for the job he did as host.

He outmaneuvered David Letterman for the gig in 1992, to the dismay of the then-"Late Night" host and Carson, among others. After reluctantly stepping down in favor of Conan O'Brien in 2009, Leno moved his act to 10 p.m. and jumped back the next year after "Tonight Show" ratings dropped.

He's also received flack from some critics for his lack of cutting-edge humor, even if many home viewers seemed to enjoy his "Headlines" and "Jaywalking" segments, among other bits. The generally amiable Leno also succeeded in making an array of guests feel comfortable – including President Obama, who became the first sitting chief executive to visit "Tonight" in 2009.

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Leno never wielded the late night game-changing influence of Letterman, whose acolytes include competitors (and Leno nemeses) O'Brien and Jimmy Kimmel. But even if he didn't always please his detractors, Leno showed he always knew how to please a crowd – especially with his opening monologues.

The guests on Leno's last show Thursday include Billy Crystal, who was his first "Tonight" visitor in 1992. Leno, no doubt, will hear plenty of accolades, but perhaps none as touching as the last thank-you note delivered by Fallon, who helped make a tough transition more sweet than bitter.

“Thank you, Jay Leno,” Fallon said, “for carrying on the proud tradition of ‘The Tonight Show’ host with such humor and class and for being nothing but gracious and generous to me over the past years. I will do my best to make you proud every single night. Thank you."